1. Field of the Invention
Aspects of the present invention relate to a touch screen display apparatus, and more particularly, to an organic light emitting display device with a touch screen function that easily detects a user's touch.
2. Description of the Related Art
Many display apparatuses are now designed to have a touch panel function. When a touch panel function is incorporated into a display apparatus that primarily has a displaying function, the display apparatus can also be made to function as an input apparatus through touching a surface of a panel of the display apparatus with a finger or pen.
Touch panels can be classified into external type touch panels and internal type touch panels, according to the position of a unit detecting a user's touch. External type touch panels include pressure-type touch panels detecting a change in pressure due to a touch, electric field-type touch panels detecting a change in an electric field due to a touch, and resistance layer-type touch panels detecting a change in resistance due to a touch. Internal type touch panels use auto brightness control (ABC), a P-I-N photo diode (junction), or a photo sensor.
In the case of an internal type touch panel, the touched portion on a screen of the touch panel can be detected using light emitted from an organic light emitting display device operating as a light source in a dark environment. However, when the intensity of the light is weak compared to the sensitivity of the photo sensor, it is not easy to detect the light. In addition, since light emitted from a light source that is not related to a touch may also be incident directly on the photo sensor, touch errors may be generated.